Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can easily trigger avalanches where easterly winds build fresh slabs on lee aspects near ridges, particularly at mid and upper elevations. Identify areas of wind-driven snow by looking for actively blowing snow or pillow-like drifts of snow that sound hollow. Consider sticking to wind-sheltered areas or choosing low angle slopes if you are traveling in sparsely treed areas exposed to wind. Cold temperatures with even colder wind chill values will be another hazard to consider on Thursday.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Thursday will usher in a day of strong easterly flow through the mountain passes. With plenty of fresh low density snow to blow around and moderate to strong east winds, you can expect new, sensitive wind slabs to form in exposed areas and near ridges. These wind slabs may rest over very light, low density snow and be easy to trigger. In addition, there is still a possibility of triggering more stubborn wind slabs that formed during the storm on Tuesday. These may be lingering under a few inches of fresh snow on opposing aspects. 

    Keep your senses tuned into the snow and use your probe or ski pole to feel for stiff layers of snow over softer layers. If you observe long shooting cracks or find hollow-sounding pillows of snow, you are traveling on or near a wind slab. You should identify these wind loaded areas and steer around steep terrain features where you find them. Sticking to wind-sheltered areas or lower angle slopes will be your best bet to avoid triggering or being caught in an avalanche. 

    (12/20/2022)

    WSDOT's avalanche team triggered this slab in wind-loaded terrain on 12/20 during their mitigation work. It reportedly failed at the new/old interface.

    Photo: WSDOT Avalanche Team

Avalanche Discussion

The very active and stormy day on Tuesday came with many reports of sensitive avalanche conditions near Snoqualmie Pass. On Wednesday, reports from Alpental Ski Patrol and WSDOT's avalanche team suggest more stubborn avalanche conditions, with lingering instabilities in wind-loaded areas. Avalanches appeared to be failing at the new/old interface, but the 12/18 interface also showed up in snowpit tests. There were also isolated areas of collapsing and a fragile melt-freeze crust in many locations. Even with conditions that seem to be improving, we are not too far from the storm that brought 1-2ft of snow to the pass. After a storm, it is always important to give yourself larger margins of safety in your terrain choices and observe how well the new snow bonds to the old snow surface. Jumping, skiing, or snowmobiling over small, steep test slopes is a great way to see if the new snow will slide easily.Thursday is shaping up to be the coldest day of the season. So make sure to prepare for these unusually cold temperatures with extra warm layers, face shields, and ensure those grip heaters are up and running.

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